3745-65-93
Preparation, evaluation, and response.

(A)
Before November 19, 1981, the owner or
operator must prepare an outline of a ground water quality assessment program.
The outline must describe a more comprehensive ground water monitoring program
than that described in rules
3745-65-91 and
3745-65-92 of the Administrative
Code, which must be capable of determining:

(2)
The rate and extent of migration of
hazardous waste or hazardous waste constituents in the ground water; and

(3)
The concentrations of
hazardous waste or hazardous waste constituents in the ground water.

(B)
For each indicator parameter
specified in paragraph (B)(3) of rule
3745-65-92 of the Administrative
Code, the owner or operator must calculate the arithmetic mean and variance,
based on at least four replicate measurements on each sample, for each well
monitored in accordance with paragraph (D)(2) of rule
3745-65-92 of the Administrative
Code, and compare these results with its initial background arithmetic mean.
The comparison must consider individually each of the wells in the monitoring
system, and must use the"Student's T-test" at the 0.01 level of significance
(see the appendix to this rule) to determine statistically significant
increases, and decreases in the case of pH, over initial background.

(1)
If
the comparisons for the upgradient wells made under paragraph (B) of this rule
show a significant increase, or pH decrease, the owner or operator must submit
this information in accordance with paragraph (A)(2)(b) of rule
3745-65-94 of the Administrative
Code.

(2)
If the comparisons for
downgradient wells made under paragraph (B) of this rule show a significant
increase, or pH decrease, the owner or operator must then immediately obtain
additional ground water samples from those downgradient wells where a
significant difference was detected, split the samples in two, and obtain
analyses of all additional samples to determine whether the significant
difference was a result of laboratory error.

(1)
If
the analyses performed under paragraph (C)(2) of this rule confirm the
significant increase, or pH decrease, the owner or operator must provide
written notice to the director, within seven days after the date of
such confirmation, that the facility may be affecting ground water quality

(2)
Within fifteen days after the
notification under paragraph (D)(1) of this rule, the owner or operator must
develop and submit to the director a specific plan, based on the outline
required under paragraph (A) of this rule and certified by a qualified
geologist or geotechnical engineer, for a ground water quality assessment
at the facility.

(3)
The plan to be submitted under paragraph
(D)(1) of rule
3745-65-90 of the Administrative
Code or paragraph (D)(2) of this rule must specify:

(4)
The
owner or operator must implement the ground water quality assessment plan which
satisfies the requirements of paragraph (D)(3) of this rule, and, at a minimum,
determine:

(a)
The rate and extent of
migration of the hazardous waste or hazardous waste constituents in the ground
water; and

(b)
The concentrations
of the hazardous waste or hazardous waste constituents in the ground water.

(5)
The owner or
operator must make his first determination under paragraph (D)(4) of this rule
as soon as technically feasible, and, within fifteen days after that
determination, submit to the director a written report containing an assessment
of the ground water quality.

(6)
If the owner or operator determines, based on the results of the first
determination under paragraph (D)(4) of this rule, that no hazardous waste or
hazardous waste constituents from the facility have entered the ground water,
then he may reinstate the indicator evaluation program described in rule
3745-65-92 of the Administrative
Code and paragraph (B) of this rule. If the owner or operator reinstates the
indicator evaluation program, he must so notify the director in the report
submitted under paragraph (D)(5) of this rule.

(7)
If the owner or operator determines,
based on the first determination under paragraph (D)(4) of this rule, that
hazardous waste or hazardous waste constituents from the facility have entered
the ground water, then he:

(a)
Must continue
to make the determinations required under paragraph (D)(4) of this rule on a
quarterly basis until final closure of the facility, if the ground water
quality assessment plan was implemented prior to final closure of the facility;
or

(b)
May cease to make the
determinations required under paragraph (D)(4) of this rule, if the ground
water quality assessment plan was implemented during the post-closure care
period.

(E)
Notwithstanding any other provision in rules
3745-65-90 to
3745-65-94 of the Administrative
Code, any ground water quality assessment to satisfy the requirements of
paragraph (D)(4) of this rule which is initiated prior to final closure of the
facility must be completed and reported in accordance with paragraph (D)(5) of
this rule.

(F)
Unless the ground
water is monitored to satisfy the requirements of paragraph (D)(4) of this
rule, at least annually the owner or operator must evaluate the data on ground
water surface elevations obtained under paragraph (E) of rule
3745-65-92 of the Administrative
Code to determine whether the requirements under paragraph (A) of rule
3745-65-91 of the Administrative
Code for locating the monitoring wells continues to be satisfied. If the
evaluation shows that paragraph (A) of rule
3745-65-91 of the Administrative
Code is no longer satisfied, the owner or operator must immediately modify the
number, location, or depth of the monitoring system into compliance with this
requirement.